Multi-phase switching power supply, control circuit thereof and dynamic voltage regulation phase number control method

Abstract

The invention discloses a multi-phase switching power supply and a control circuit and a dynamic voltage regulation phase number control method thereof, the multi-phase switching power supply comprises an N-phase power conversion circuit, N is an integer greater than or equal to 2, the output end of the multi-phase switching power supply is connected with an output capacitor and generates an output voltage, and the method comprises the following steps: judging whether the multi-phase switching power supply is in a first dynamic voltage regulation state; when the multiphase switching power supply is in a first dynamic voltage regulation state, according to a preset rate and a plurality of rate thresholds, controlling the number of working phases changed relative to the number of working phases before the first dynamic voltage regulation state; wherein the first dynamic voltage regulation state comprises a dynamic regulation output voltage rising state and / or a dynamic regulation output voltage reducing state; when the multi-phase switching power supply is in the first dynamic voltage regulation state, controlling the output voltage to change according to a preset rate; the working phase number is the phase number of the power conversion circuit for power operation. The phase number of the power conversion circuit which actually works in the dynamic voltage regulation process can be adjusted, and the system efficiency is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power electronics, and particularly relates to a multi-phase switching power supply, a control circuit thereof and a dynamic voltage regulation phase number control method. BACKGROUND

[0002] The multi-phase switching power supply comprises a multi-phase power conversion circuit, and in application, there are two working states of frequent load change and dynamic voltage regulation. For the load change working state, the current multi-phase switching power supply can autonomously optimize the number of running phases of the power conversion circuit according to the load current, so as to realize high-efficiency running in the full load range. However, for the dynamic voltage regulation working state, i.e. the dynamic adjustment of the output voltage working state, the current multi-phase switching power supply only simply maintains full-phase running, and does not change the working phase number according to the specific dynamic voltage regulation process, so as to fail to optimize the power consumption in the dynamic voltage regulation process, resulting in large power loss of the system. SUMMARY

[0003] Therefore, the present application aims to provide a multi-phase switching power supply, a control circuit thereof and a dynamic voltage regulation phase number control method, so as to solve the technical problem that the current technology only simply maintains full-phase running in the dynamic voltage regulation process, resulting in large power loss of the system in the dynamic voltage regulation process.

[0004] The technical solution of the present application is that, on one hand, a dynamic voltage regulation phase number control method of a multi-phase switching power supply is provided, the multi-phase switching power supply comprises an N-phase power conversion circuit, wherein N is an integer greater than or equal to 2, an input end of the multi-phase switching power supply receives an input voltage, an output end of the multi-phase switching power supply is connected to an output capacitor and generates an output voltage, and the dynamic voltage regulation phase number control method comprises:

[0005] judging whether the multi-phase switching power supply is in a first dynamic voltage regulation state;

[0006] when the multi-phase switching power supply is in the first dynamic voltage regulation state, controlling the number of changes of a working phase number relative to the first dynamic voltage regulation state according to a preset rate and a plurality of rate thresholds,

[0007] wherein the first dynamic voltage regulation state comprises a dynamic adjustment of an output voltage rising state and / or a dynamic adjustment of an output voltage falling state; when the multi-phase switching power supply is in the first dynamic voltage regulation state, the output voltage is controlled to change at the preset rate; and the working phase number is the number of phases of the power conversion circuit that performs power running.

[0008] Optionally, when the first dynamic voltage adjustment state comprises a dynamic output voltage increasing state, the preset rate comprises a boost preset rate, and the plurality of rate thresholds comprises a plurality of boost rate thresholds, the number of operating phases is controlled according to the boost preset rate and the plurality of boost rate thresholds when the multi-phase switching power supply is in the dynamic output voltage increasing state.

[0009] When the first dynamic voltage adjustment state comprises a dynamic output voltage decreasing state, the preset rate comprises a buck preset rate, and the plurality of rate thresholds comprises a plurality of buck rate thresholds, the number of operating phases is controlled according to the buck preset rate and the plurality of buck rate thresholds when the multi-phase switching power supply is in the dynamic output voltage decreasing state.

[0010] Optionally, the number of operating phases that needs to be controlled to change relative to the first dynamic voltage adjustment state is obtained according to the preset rate and the plurality of rate thresholds.

[0011] The number of operating phases that needs to be controlled to change relative to the first dynamic voltage adjustment state is obtained according to the preset rate and the plurality of rate thresholds.

[0012] Optionally, the number of operating phases that needs to be controlled to change relative to the first dynamic voltage adjustment state is positively correlated with the preset rate.

[0013] Optionally, when the multi-phase switching power supply is in the first dynamic voltage adjustment state, the number of operating phases that needs to be controlled to change relative to the first dynamic voltage adjustment state is obtained by processing the plurality of rate thresholds with a rate threshold bias.

[0014] Optionally, when the multi-phase switching power supply is in the first dynamic voltage adjustment state, the plurality of rate thresholds are processed with a rate threshold bias to obtain a plurality of processed rate thresholds, and the number of operating phases that needs to be controlled to change relative to the steady state before dynamic voltage adjustment is controlled according to a comparison between the preset rate and the plurality of processed rate thresholds.

[0015] Optionally, the rate threshold bias is adjustable.

[0016] Optionally, when the first dynamic voltage adjustment state comprises a dynamic output voltage increasing state, the rate threshold bias comprises a first rate threshold bias, the plurality of boost rate thresholds are processed with the first rate threshold bias to obtain a plurality of processed boost rate thresholds, and the plurality of processed boost rate thresholds are equal to the plurality of boost rate thresholds minus the first rate threshold bias.

[0017] wherein the first rate threshold offset is greater than or equal to zero.

[0018] Optionally, when the first dynamic voltage regulation state comprises a dynamic adjustment output voltage decrease state, the rate threshold offset comprises a second rate threshold offset, the plurality of buck rate threshold values are processed with the second rate threshold offset to obtain a plurality of processed buck rate threshold values, the plurality of processed buck rate threshold values are equal to the plurality of buck rate threshold values plus the second rate threshold offset.

[0019] wherein the second rate threshold offset is greater than or equal to zero.

[0020] Optionally, when the first dynamic voltage regulation state comprises a dynamic adjustment output voltage increase state, and the number of controlled working phases is increased by a number greater than or equal to 1, at a time when the multi-phase switching power supply starts to enter the dynamic adjustment output voltage increase state, a corresponding number of power conversion circuits which do not perform power operation are controlled to start to perform power operation.

[0021] Optionally, when the first dynamic voltage regulation state comprises a dynamic adjustment output voltage decrease state, and the number of controlled working phases is decreased by a number greater than or equal to 2, at a time when the multi-phase switching power supply is in the dynamic adjustment output voltage decrease state, the number of power conversion circuits which perform power operation is successively decreased.

[0022] Optionally, the plurality of rate threshold values are set according to the capacitance of the output capacitor, and the plurality of rate threshold values are negatively related to the capacitance of the output capacitor.

[0023] Optionally, the plurality of rate threshold values are obtained according to an optimal efficiency curve of the multi-phase switching power supply and the capacitance of the output capacitor.

[0024] Optionally, an optimal switching load current is obtained according to the optimal efficiency curve, and the plurality of rate threshold values are obtained according to a quotient of a difference between at least two optimal switching load currents and the capacitance of the output capacitor.

[0025] wherein the optimal switching load current is a load current corresponding to an intersection point of efficiency curves of adjacent working phases of the optimal efficiency curve.

[0026] Optionally, when the multi-phase switching power supply is in a steady state, a working phase number of the multi-phase switching power supply is controlled according to a load current sampling signal and a plurality of current threshold values.

[0027] the plurality of rate threshold values are obtained according to at least two current threshold values of the plurality of current threshold values and the capacitance of the output capacitor.

[0028] The plurality of rate thresholds are obtained according to a quotient of a difference between the current thresholds and a capacitance of the output capacitor.

[0029] Optionally, the plurality of rate thresholds are also set according to a number of operating phases before the first dynamic voltage regulation state.

[0030] Optionally, the multiphase switching power supply receives a rate instruction, and the preset rate is set according to the rate instruction.

[0031] In a second aspect, the present application provides a control circuit of a multiphase switching power supply, the multiphase switching power supply comprising N-phase power conversion circuits, where N is an integer greater than or equal to 2, an input end of the multiphase switching power supply receiving an input voltage, and an output end of the multiphase switching power supply being connected to an output capacitor and generating an output voltage,

[0032] The control circuit determines whether the multiphase switching power supply is in a first dynamic voltage regulation state.

[0033] When the multiphase switching power supply is in the first dynamic voltage regulation state, the control circuit controls a number of changes of the number of operating phases relative to before the first dynamic voltage regulation state according to a preset rate and a plurality of rate thresholds.

[0034] The first dynamic voltage regulation state comprises a dynamic adjustment of an output voltage increase state and / or a dynamic adjustment of an output voltage decrease state; when the multiphase switching power supply is in the first dynamic voltage regulation state, the control circuit controls the output voltage to change at the preset rate; and the number of operating phases is the number of power conversion circuits that are in power operation.

[0035] Optionally, the control circuit comprises:

[0036] a state determination module that detects an operating state of the multiphase switching power supply, determines whether the multiphase switching power supply is in the first dynamic voltage regulation state, and outputs a state determination signal;

[0037] a dynamic voltage regulation phase number control circuit that receives the state determination signal, and when the state determination signal indicates that the multiphase switching power supply is in the first dynamic voltage regulation state, outputs a dynamic voltage regulation phase number control signal according to the preset rate and the plurality of rate thresholds.

[0038] The control circuit controls the number of changes of the number of operating phases relative to before the first dynamic voltage regulation state according to the dynamic voltage regulation phase number control signal.

[0039] In a second aspect, the present application provides a multiphase switching power supply comprising the control circuit or using the dynamic voltage regulation phase number control method to control a number of changes of the number of operating phases of the multiphase switching power supply.

[0040] Compared with the prior art, the circuit structure has the following advantages: when the multi-phase switching power supply is in a first dynamic voltage regulating state, the number of working phases is controlled according to a preset rate and a plurality of rate thresholds relative to the number of changes before the first dynamic voltage regulating state, so that the power consumption in the dynamic voltage regulating process is optimized, and the efficiency of the system in the dynamic voltage regulating state is improved. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 A flowchart of a dynamic voltage regulating phase number control method of a multi-phase switching power supply according to an embodiment of the present application is provided.

[0042] Figure 2 A working phase number change diagram of an embodiment of the present application is provided.

[0043] Figure 3 A working phase number change diagram of another embodiment of the present application is provided.

[0044] Figure 4 An efficiency curve diagram of a multi-phase switching power supply of an embodiment of the present application is provided.

[0045] Figure 5 A circuit structure diagram of a multi-phase switching power supply of an embodiment of the present application is provided. DETAILED DESCRIPTION

[0046] The preferred embodiments of the present application are described in detail below with reference to the accompanying drawings, but the present application is not limited to these embodiments. The present application covers any alternatives, modifications, equivalent methods and solutions within the spirit and scope of the present application.

[0047] In order to make the public have a thorough understanding of the present application, specific details are described in the following preferred embodiments of the present application, and the present application can also be fully understood without the description of these details by those skilled in the art.

[0048] The present application is described in more detail in the following paragraphs with reference to the accompanying drawings. It should be noted that the drawings are in a simplified form and use non-precise proportions, and are only used to facilitate and clearly assist the purpose of describing the embodiments of the present application.

[0049] REFERENCE Figure 5The multi-phase switching power supply is a power supply including N-phase power conversion circuits, where N is an integer greater than or equal to 2, and the output end of the multi-phase switching power supply is connected to an output capacitor to generate an output voltage and an output current provided to a load, the output capacitor is coupled between the output end of the multi-phase switching power supply and a reference ground, and the voltage on the output capacitor is the output voltage. During dynamic voltage regulation of the multi-phase switching power supply, the output voltage dynamically changes, accompanied by charging and discharging of the output capacitor, which causes changes in the output current, i.e., changes in the load current, at which time the number of operating phases that is most efficient should change. According to the fact that the current on the output capacitor is proportional to dVo / dt, where Vo represents the output voltage and t represents time, and dVo / dt represents the rate of change of the output voltage, it can be seen that different rates of change of the output voltage correspond to different changes in the output current, and the number of phases required to achieve optimal efficiency is also different. Based on this, the present application proposes a dynamic voltage regulation phase number control method for a multi-phase switching power supply, a flowchart is shown in Figure 1 as shown, comprising:

[0050] In step S10, it is determined whether the multi-phase switching power supply is in a first dynamic voltage regulation state. The first dynamic voltage regulation state includes a dynamic output voltage increase state and / or a dynamic output voltage decrease state.

[0051] The method for determining whether the multi-phase switching power supply is in the first dynamic voltage regulation state is not limited in the embodiments of the present application, and any method in the prior art can be used. For example, the multi-phase switching power supply receives a voltage identification code (VID) sent by a processor, and adjusts its output voltage according to the voltage identification code. The dynamic voltage regulation process is a process in which the multi-phase switching power supply dynamically adjusts its output voltage according to changes in the voltage identification code. In an embodiment, whether the multi-phase switching power supply is in the first dynamic voltage regulation state can be determined by detecting the state of the voltage identification code, for example, by detecting whether the voltage identification code changes to satisfy a predetermined condition.

[0052] In step S20, when the multi-phase switching power supply is in the first dynamic voltage regulation state, the number of operating phases is controlled to change relative to the number of changes before the first dynamic voltage regulation state according to a predetermined rate and a plurality of rate thresholds. When the multi-phase switching power supply is in the first dynamic voltage regulation state, the output voltage changes at the predetermined rate, i.e., the rate of change of the output voltage is controlled according to the predetermined rate, and the predetermined rate can represent the rate of change of the output voltage. The number of operating phases is the number of phases of the power conversion circuit that performs power operation.

[0053] In one embodiment, the first dynamic voltage regulating state can be set to include a dynamic output voltage increasing state, the preset rate can be set to include a voltage increasing preset rate, and the plurality of rate thresholds can be set to include a plurality of voltage increasing rate thresholds, and the number of operating phases to be increased before the dynamic output voltage increasing state can be controlled according to the voltage increasing preset rate and the plurality of voltage increasing rate thresholds. In another embodiment, the first dynamic voltage regulating state can be set to include a dynamic output voltage decreasing state, the preset rate can be set to include a voltage decreasing preset rate, and the plurality of rate thresholds can be set to include a plurality of voltage decreasing rate thresholds, and the number of operating phases to be decreased before the dynamic output voltage decreasing state can be controlled according to the voltage decreasing preset rate and the plurality of voltage decreasing rate thresholds. In yet another embodiment, the first dynamic voltage regulating state can be set to include a dynamic output voltage increasing state and a dynamic output voltage decreasing state, the preset rate can be set to include a voltage increasing preset rate and a voltage decreasing preset rate, and the plurality of rate thresholds can be set to include a plurality of voltage increasing rate thresholds and a plurality of voltage decreasing rate thresholds, the number of operating phases to be increased before the first dynamic voltage regulating state can be controlled according to the voltage increasing preset rate and the plurality of voltage increasing rate thresholds, and the number of operating phases to be decreased before the first dynamic voltage regulating state can be controlled according to the voltage decreasing preset rate and the plurality of voltage decreasing rate thresholds, wherein the voltage increasing preset rate and the voltage decreasing preset rate can be set to be equal or not equal, and the plurality of voltage increasing rate thresholds and the plurality of voltage decreasing rate thresholds can be set to be equal one-to-one or not equal one-to-one.

[0054] According to the preset rate and the plurality of rate thresholds, the method of controlling the number of working phases changed before the first dynamic voltage regulation state further comprises: obtaining a number of working phases needed to be controlled to change before the first dynamic voltage regulation state according to the preset rate and the plurality of rate thresholds; and controlling the number of working phases changed before the first dynamic voltage regulation state according to the number of working phases needed to be controlled to change before the first dynamic voltage regulation state and the number of working phases before the first dynamic voltage regulation state. For example, when the sum of the number of working phases before the first dynamic voltage regulation state and the number of working phases needed to be controlled to increase is less than or equal to the maximum number of working phases set by the multi-phase switching power supply, the number of working phases controlled to increase is equal to the number of working phases needed to be controlled to increase, otherwise, the number of working phases controlled to increase is equal to the difference between the maximum number of working phases and the number of working phases before the first dynamic voltage regulation state, wherein the maximum number of working phases can be set to N for example; when the difference between the number of working phases before the first dynamic voltage regulation state and the number of working phases needed to be controlled to decrease is greater than or equal to the minimum number of working phases set by the multi-phase switching power supply, the number of working phases controlled to increase is equal to the number of working phases needed to be controlled to decrease, otherwise, the number of working phases controlled to decrease is equal to the difference between the number of working phases before the first dynamic voltage regulation state and the minimum number of working phases, wherein the minimum number of working phases can be set to 1 for example. Since the current on the output capacitor is proportional to the rate of change of the output voltage, setting the number of working phases needed to be controlled to change before the first dynamic voltage regulation state to be positively correlated with the preset rate can achieve higher efficiency. Since the current on the output capacitor is proportional to the capacitance of the output capacitor, at the same preset rate, the greater the capacitance of the output capacitor, the greater the current on the output capacitor, and the greater the number of working phases needed to change to achieve optimal efficiency. Therefore, setting the number of working phases needed to be controlled to change before the first dynamic voltage regulation state to be positively correlated with the capacitance of the output capacitor can further improve efficiency. To achieve the positive correlation between the number of working phases needed to be controlled to change before the first dynamic voltage regulation state and the capacitance of the output capacitor, the plurality of rate thresholds can be set according to the capacitance of the output capacitor, and the plurality of rate thresholds can be set to be negatively correlated with the capacitance of the output capacitor.

[0055] According to the relationship between the preset rate and the plurality of rate thresholds, the number of changes of the working phase relative to the first dynamic voltage regulation state is controlled. In some embodiments, the number of changes of the working phase relative to the first dynamic voltage regulation state is obtained according to the comparison result between the preset rate and the plurality of rate thresholds, and then the number of changes of the working phase relative to the first dynamic voltage regulation state is controlled. In other embodiments, the plurality of rate thresholds are processed by using a rate threshold offset to obtain a plurality of processed rate thresholds, and then the number of changes of the working phase relative to the first dynamic voltage regulation state is controlled according to the comparison result between the preset rate and the plurality of processed rate thresholds. The rate threshold offset can be adjustable, and the number of changes of the working phase relative to the first dynamic voltage regulation state is flexibly set by adjusting the size of the rate threshold offset. When the first dynamic voltage regulation state includes a dynamic output voltage increase state, the rate threshold offset includes a first rate threshold offset, the plurality of boost rate thresholds are processed by using the first rate threshold offset to obtain a plurality of processed boost rate thresholds, the plurality of processed boost rate thresholds are equal to the difference between the plurality of boost rate thresholds and the first rate threshold offset, and the first rate threshold offset is greater than or equal to zero. The number of changes of the working phase relative to the dynamic output voltage increase state is controlled according to the comparison result between the boost preset rate and the plurality of processed boost rate thresholds. The beneficial effects of such a setting include at least: (1) when a large first rate threshold offset is set, the plurality of processed boost rate thresholds are very small or even less than zero, and a very small boost preset rate can meet the requirement of full-phase operation, so that the system operates in full phase during the dynamic output voltage increase state. This setting can cover the existing full-phase operation scenario in the dynamic voltage regulation process, and better compatible with the existing application scenario; (2) under the condition that the output capacitor has a very small capacitance, the plurality of boost rate thresholds will be very large, and the boost preset rate range is not enough to trigger the phase addition. At this time, a suitable first rate threshold offset is set to trigger the phase addition condition, and the phase addition in the dynamic output voltage increase state under the condition of a small-capacitance output capacitor can be more flexibly realized; (3) in some embodiments, the multi-phase switching power supply receives a rate instruction and sets the preset rate according to the rate instruction. For example, when the rate instruction is divided into Fast (fast) instruction and slow (slow) instruction, the multi-phase switching power supply sets different boost preset rates according to different rate instructions. The dynamic output voltage increase can be divided into Fast / Slow two scenarios. A reasonable first rate threshold offset is set to realize full-phase operation in the Fast scenario of dynamic output voltage increase, and not full-phase operation in the Slow scenario of dynamic output voltage increase, so that the Fast / Slow two scenarios of dynamic output voltage increase can be more flexibly processed.When the first dynamic voltage regulation state comprises a dynamic output voltage decrease state, the rate threshold bias comprises a second rate threshold bias, the plurality of decreased rate thresholds can be processed using the second rate threshold bias to obtain a plurality of processed decreased rate thresholds, the second rate threshold bias is greater than or equal to zero, the plurality of processed decreased rate thresholds are equal to the sum of the plurality of decreased rate thresholds and the second rate threshold bias, and the number of operating phases changed relative to before the dynamic output voltage decrease state is controlled according to the comparison result between the decreased preset rate and the plurality of processed decreased rate thresholds. The beneficial effects of this arrangement include at least: (1) when a large second rate threshold bias is set, the plurality of processed decreased rate thresholds are large, and the decreased preset rate range is insufficient to trigger phase reduction. By setting an adjustable second rate threshold bias, the dynamic output voltage decrease can be flexibly implemented without phase reduction or with phase reduction; (2) under the condition that the output capacitor has a large capacitance, the plurality of decreased rate thresholds will be very small, and the decreased preset rate range will easily trigger a reduction to one phase. At this time, by setting a suitable second rate threshold bias, the phase reduction condition will not be easily triggered, and the selective phase reduction under the condition of a large-capacitance output capacitor during the dynamic output voltage decrease state can be more flexibly implemented; (3) when the dynamic output voltage decrease can be divided into Fast / Slow two scenarios, by setting a reasonable second rate threshold bias, the phase reduction during the Fast scenario of the dynamic output voltage decrease and the non-phase reduction during the Slow scenario of the dynamic output voltage decrease can be implemented, and the Fast / Slow two scenarios of the dynamic output voltage increase can be more flexibly processed. When the first dynamic voltage regulation state comprises a dynamic output voltage increase state and a dynamic output voltage decrease state, the rate threshold bias can be set to comprise a first rate threshold bias, or a second rate threshold bias, or a first rate threshold bias and a second rate threshold bias. When the rate threshold bias comprises a first rate threshold bias and a second rate threshold bias, the first rate threshold bias and the second rate threshold bias can be set to be equal or not equal.

[0056] It should be noted that the embodiment of the present application controls the number of changes of the working phase relative to the first dynamic voltage regulation state by using a preset rate, rather than using the change rate of the output voltage in the first dynamic voltage regulation state obtained by detection, to control the number of changes of the working phase relative to the first dynamic voltage regulation state. The detection methods include, for example, detecting the change rate of a signal capable of representing the output voltage to obtain the change rate of the output voltage in the first dynamic voltage regulation state; or detecting the current on the output capacitor to obtain the change rate of the output voltage in the first dynamic voltage regulation state; and the like. These detection methods all need a certain detection time. The preset rate is a known quantity for the multiphase switching power supply, so the embodiment of the present application does not need to go through the time of detecting the change rate of the output voltage after the multiphase switching power supply enters the first dynamic voltage regulation state, and can timely control the number of changes of the working phase relative to the first dynamic voltage regulation state, thereby improving the efficiency and avoiding the output voltage drop phenomenon caused by the failure to timely increase the number of working phases.

[0057] When the first dynamic voltage regulation state includes a dynamic output voltage increase adjustment state, and the number of controlled increases of the working phase is greater than or equal to 1, to prevent the output voltage from falling too much, the number of increases of the working phase can be set to be fast, that is, at the moment when the multiphase switching power supply starts to enter the dynamic output voltage increase adjustment state, a corresponding number of power conversion circuits that do not perform power operation are simultaneously controlled to start power operation. For details, refer to Figure 2 , Figure 2 The number of increases of the working phase in the dynamic output voltage increase adjustment state is shown to be equal to 2, the multiphase switching power supply is in a steady state in the t10-t11 time period, the number of working phases is 1, the multiphase switching power supply is in a dynamic output voltage increase adjustment state in the t11-t12 time period, at the moment when the multiphase switching power supply starts to enter the dynamic output voltage increase adjustment state (that is, at the t11 moment), two power conversion circuits that do not perform power operation are simultaneously controlled to start power operation, and the number of working phases is kept to be 3 in the t11-t12 time period.

[0058] When the first dynamic voltage regulation state includes a dynamic output voltage decrease adjustment state, and the number of controlled decreases of the working phase is greater than or equal to 2, the number of decreases of the working phase can be set to be slow, that is, the number of power conversion circuits that perform power operation can be gradually reduced when the multiphase switching power supply is in the dynamic output voltage decrease adjustment state. For details, refer to Figure 3 , Figure 3The number of the working phases is reduced by 2 in the dynamic adjustment of the output voltage reduction state. The multi-phase switching power supply is in steady state in the time period from t20 to t21, and the number of the working phases is 4. The multi-phase switching power supply is in the dynamic adjustment of the output voltage reduction state in the time period from t21 to t23. At the time when the multi-phase switching power supply starts to enter the dynamic adjustment of the output voltage reduction state (at the time t21), one of the 4-phase power conversion circuits for power operation is controlled to stop working. The number of the working phases is 3 in the time period from t21 to t22. At the time t22, one of the 3-phase power conversion circuits for power operation is controlled to stop working. The number of the working phases is 2 in the time period from t21 to t22.

[0059] Further, the embodiment of the present application also provides a method for obtaining the plurality of rate thresholds. In some embodiments, the plurality of rate thresholds can be obtained according to the optimal efficiency curve of the multi-phase switching power supply and the capacitance of the output capacitor. Further, the optimal switching load current is obtained according to the optimal efficiency curve, and the plurality of rate thresholds is obtained according to at least two optimal switching load currents and the capacitance of the output capacitor. Further, the plurality of rate thresholds is obtained according to the quotient of the difference between at least two optimal switching load currents and the capacitance of the output capacitor. The optimal switching load current is the load current corresponding to the intersection point of the efficiency curves of the adjacent working phases of the optimal efficiency curve. The specific method can be introduced below taking the efficiency curve of the multi-phase switching power supply shown in the figure as an example. Figure 4 The specific method can be introduced below taking the efficiency curve of the multi-phase switching power supply shown in the figure as an example. Figure 4The efficiency curves of 1-phase, 2-phase, 3-phase and 4-phase are shown, I1, I2 and I3 represent the optimal switching load currents, I1, I2 and I3 are the load currents corresponding to the intersection points of 1-phase-2-phase efficiency curve (hereinafter referred to as 1-phase-2-phase intersection point), 2-phase-3-phase efficiency curve (hereinafter referred to as 2-phase-3-phase intersection point) and 3-phase-4-phase efficiency curve (hereinafter referred to as 3-phase-4-phase intersection point) respectively, the corresponding working phase number is changed when the load current of the multi-phase switching power supply reaches the optimal switching load current I1, I2 and I3, and the obtained efficiency curve is the optimal efficiency curve. In an embodiment, a plurality of rate thresholds can be obtained according to the optimal switching load current I1 corresponding to the 1-phase-2-phase intersection point and the optimal switching load current I2 corresponding to the 2-phase-3-phase intersection point and the capacitance Co of the output capacitor, and the plurality of rate thresholds can be set to be equal to (I2-I1) / Co, 2*(I2-I1) / Co…(N-1)*(I2-I1) / Co respectively. The following examples are introduced without setting the rate threshold bias, and the plurality of boost rate thresholds and the plurality of buck rate thresholds are equal one by one, that is, the plurality of boost rate thresholds are equal to (I2-I1) / Co, 2*(I2-I1) / Co…(N-1)*(I2-I1) / Co respectively, and the plurality of buck rate thresholds are also equal to (I2-I1) / Co, 2*(I2-I1) / Co…(N-1)*(I2-I1) / Co respectively, when the first dynamic voltage regulation state includes a dynamic output voltage increase adjustment state, the switching power supply is in the dynamic output voltage increase adjustment state,

[0060] If 2*(I2-I1) / Co>SR1≥(I2-I1) / Co, the working phase number needs to be increased by 1;

[0061] If 3*(I2-I1) / Co>SR1≥2*(I2-I1) / Co, the working phase number needs to be increased by 2;

[0062] Similarly,

[0063] If (N-1)*(I2-I1) / Co>SR1≥(N-2)*(I2-I1) / Co, the working phase number needs to be increased by N-2;

[0064] If SR1≥(N-1)*(I2-I1) / Co, the working phase number needs to be increased by N-1;

[0065] Wherein SR1 represents the boost preset slope.

[0066] When the first dynamic voltage regulation state includes a dynamic output voltage decrease adjustment state, the switching power supply is in the dynamic output voltage decrease adjustment state,

[0067] If 2*(I2-I1) / Co>SR2≥(I2-I1) / Co, the number of working phases needs to be controlled to decrease by 1;

[0068] If 3*(I2-I1) / Co>SR2≥2*(I2-I1) / Co, the number of working phases needs to be controlled to decrease by 2;

[0069] By analogy,

[0070] If (N-1)*(I2-I1) / Co>SR2≥(N-2)*(I2-I1) / Co, the number of working phases needs to be controlled to decrease by N-2;

[0071] If SR2≥(N-1)*(I2-I1) / Co, the number of working phases needs to be controlled to decrease by N-1;

[0072] Wherein, SR2 represents the preset slope of voltage reduction.

[0073] The skilled in the art can completely obtain the situation of setting the rate threshold bias according to the above introduction, and will not be repeated here. It is easy to understand that in another embodiment, a plurality of rate threshold values can also be obtained according to the optimal switching load current I2 corresponding to the 2-phase-3-phase intersection point and the optimal switching load current I3 corresponding to the 3-phase-4-phase intersection point and the capacitance value of the output capacitor, and the plurality of rate threshold values can be set to be equal to (I3-I2) / Co, 2*(I3-I2) / Co…(N-1)*(I3-I2) / Co respectively. In yet another embodiment, a plurality of rate threshold values can also be obtained according to the optimal switching load current I1 corresponding to the 1-phase-2-phase intersection point and the optimal switching load current I3 corresponding to the 3-phase-4-phase intersection point and the capacitance value of the output capacitor, and the plurality of rate threshold values can be set to be equal to (I3-I1) / (2*Co), 2*(I3-I1) / (2*Co)…(N-1)*(I3-I1) / (2*Co) respectively, wherein Co represents the capacitance value of the output capacitor.

[0074] The above are examples of obtaining multiple rate thresholds only according to two optimal switching load currents and the capacitance of the output capacitor, the multiple rate thresholds form an arithmetic sequence, the method of obtaining the multiple rate thresholds is simple, but there may be a case that the actual change amount of the number of operating phases in the first dynamic voltage regulation state differs from the ideal change amount, resulting in that the efficiency in the first dynamic voltage regulation state does not reach the highest. To improve the efficiency in the first dynamic voltage regulation state and make the actual change amount of the number of operating phases in the first dynamic voltage regulation state closer to the ideal change amount, in other embodiments, multiple rate thresholds can also be obtained according to a larger number of optimal switching load currents and the capacitance of the output capacitor. An embodiment of obtaining multiple rate thresholds according to all optimal switching load currents and the capacitance of the output capacitor is introduced below, which has different rate thresholds when the number of operating phases before the first dynamic voltage regulation state is different, and the details are as follows. Suppose that the optimal switching load currents are I1, I2, I3, … I(N-1) respectively, which are the load currents corresponding to the intersection points of the 1-phase-2-phase intersection point, the 2-phase-3-phase intersection point, the 3-phase-4-phase intersection point, …, and the (N-1)-phase-N-phase efficiency curves, and the first dynamic voltage regulation state includes a dynamic output voltage increasing state and a dynamic output voltage decreasing state.

[0075] When the number of operating phases before the first dynamic voltage regulation state is equal to 1, N-1 boost rate thresholds are set, which are (I2-I1) / Co, [(I2-I1)+(I2-I1)] / Co, [(I2-I1)+(I3-I1)] / Co, …, and [(I2-I1)+(I(N-1)-I1)] / Co, and no buck rate threshold needs to be set.

[0076] When the number of operating phases before the first dynamic voltage regulation state is equal to 2, N-2 boost rate thresholds are set, which are (I2-I1) / Co, (I3-I1) / Co, …, and (I(N-1)-I1) / Co, and one buck rate threshold is set, which is (I2-I1) / Co.

[0077] When the number of operating phases before the first dynamic voltage regulation state is equal to 3, N-3 boost rate thresholds are set, which are (I3-I2) / Co, (I4-I2) / Co, …, and (I(N-1)-I2) / Co, and two buck rate thresholds are set, which are (I3-I2) / Co and (I3-I1) / Co.

[0078] When the number of working phases before the first dynamic voltage regulating state is equal to M, M is an integer greater than 3 and less than N, then N-M boost rate thresholds are set, respectively: (I M-I(M-1)) / Co, (I(M+1)-I(M-1)) / Co…(I(N-1)-I(M-1)) / Co, and M-1 drop rate thresholds are set, respectively: (I M-I(M-1)) / Co, (I M-I(M-2)) / Co…(I M-I1) / Co;

[0079] When the number of working phases before the first dynamic voltage regulating state is equal to N, then N-1 drop rate thresholds are set, respectively: (I(N-1)-I(N-2)) / Co, [(I(N-1)-I(N-2))+(I(N-1)-I(N-2))] / Co, [(I(N-1)-I(N-2))+(I(N-1)-I(N-3))] / Co…[(I(N-1)-I(N-2))+(I(N-1)-I1)] / Co, and no boost rate threshold is set.

[0080] Of course, in some other embodiments, the plurality of rate thresholds can also be obtained without the optimal efficiency curve. When the multiphase switching power supply is in steady state, the number of working phases of the multiphase switching power supply is controlled according to the load current sampling signal and the plurality of current thresholds, thus the plurality of rate thresholds can also be obtained according to at least two current thresholds in the plurality of current thresholds and the capacitance of the output capacitor. Further, the plurality of rate thresholds is obtained according to the quotient of the difference between the current thresholds and the capacitance of the output capacitor. The specific scheme can refer to the above description of obtaining the plurality of rate thresholds according to the optimal efficiency curve and the capacitance of the output capacitor, which will not be described here.

[0081] Figure 5Fig. 1 shows a schematic diagram of a multi-phase switching power supply according to an embodiment of the present application. The multi-phase switching power supply 10 includes N phase power conversion circuits 301-30N, N driving circuits 201-20N and a control circuit 100, where N is an integer greater than or equal to 2. The input of the multi-phase switching power supply 10 receives an input voltage Vin, and the output of the multi-phase switching power supply 10 is connected to an output capacitor Co and generates an output voltage Vo and an output current io to provide to a load. For example, the 1st phase power conversion circuit 401 has a Buck topology, including a first switch T1 and a second switch T2 connected between the input voltage Vin and ground, and an inductor L1 connected between the common terminal of the first and second switches T1 and T2 and the output. Of course, in other embodiments, the power conversion circuit can have any other topology, such as a Boost, Buck-Boost, Flyback, etc., and the present application is not limited in this respect. The control circuit 100 receives a voltage identification code VID, and adjusts the output voltage Vo according to the voltage identification code VID. Specifically, the voltage identification code VID is sent by a processor, for example, and the control circuit 100 controls the working state of the switches in the N phase power conversion circuits according to the voltage identification code VID and an output feedback signal FB.

[0082] The control circuit 100 judges whether the multi-phase switching power supply 10 is in the first dynamic voltage regulating state, and controls the number of working phases to change relative to the number of changes before the first dynamic voltage regulating state according to a preset speed and a plurality of speed threshold values when the multi-phase switching power supply 10 is in the first dynamic voltage regulating state. The first dynamic voltage regulating state includes a dynamic output voltage increasing state and / or a dynamic output voltage decreasing state. The control circuit 100 controls the output voltage Vo to change according to the preset speed when the multi-phase switching power supply 10 is in the first dynamic voltage regulating state. The number of working phases is the number of phases of the power conversion circuit in power operation. Specifically, the control circuit 100 includes a state judging module 101 and a dynamic voltage regulating phase number control circuit 102. The state judging module 101 detects the working state of the multi-phase switching power supply 10, judges whether the multi-phase switching power supply 10 is in the first dynamic voltage regulating state, and outputs a state judging signal. The dynamic voltage regulating phase number control circuit 102 receives the state judging signal, and outputs a dynamic voltage regulating phase number control signal according to the preset speed and the plurality of speed threshold values when the state judging signal indicates that the switching power supply 10 is in the first dynamic voltage regulating state. The control circuit 10 controls the number of working phases to change relative to the number of changes before the first dynamic voltage regulating state according to the dynamic voltage regulating phase number control signal. In an example, the state judging module 101 can judge whether the multi-phase switching power supply 10 is in the first dynamic voltage regulating state by detecting the state of the voltage identification code VID. In addition, the control circuit 10 further includes a control signal generating module 103 for generating n-phase PWM signals PWM1-PWMn according to the voltage identification code VID and the output feedback signal FB. Each driving circuit 201-20N receives a PWM signal and controls the conduction and turn-off of the switch in the corresponding power conversion circuit according to the received PWM signal. In an example, as shown in FIG. 8, the control signal generating module 103 receives the dynamic voltage regulating phase number control signal output by the dynamic voltage regulating phase number control circuit 102, and controls the number of changes of the PWM signals PWM1-PWMn in the high impedance state or the number of changes of the PWM signals PWM1-PWMn not in the high impedance state according to the dynamic voltage regulating phase number control signal to control the number of changes of the working phases. In an example, the processor further outputs a speed instruction SR_set, and the control circuit 100 receives the speed instruction SR_set and sets the preset speed according to the speed instruction SR_set. Specifically, the control signal generating module 103 controls the change slope of the output voltage Vo according to the preset speed set based on the speed instruction SR_set when in the first dynamic voltage regulating state, and the dynamic voltage regulating phase number control circuit 102 outputs the dynamic voltage regulating phase number control signal according to the preset speed set based on the speed instruction SR_set. Figure 5

[0083] ​In summary, in the embodiment of the present application, the number of working phases is controlled according to the preset speed and the plurality of speed threshold values before the first dynamic voltage regulation state changes, that is, the number of working phase changes can be different when the preset speed is different, compared with the prior art dynamic voltage regulation state which simply keeps full phase operation, and the embodiment of the present application can have higher efficiency in the dynamic voltage regulation process. When the plurality of speed threshold values are negatively related to the capacitance of the output capacitor, the larger the capacitance of the output capacitor is, the larger the number of working phase changes is, and the efficiency in the dynamic voltage regulation process is further improved. Moreover, the embodiment of the present application controls the number of working phases according to the preset speed before the first dynamic voltage regulation state changes, can timely control the number of working phases before the first dynamic voltage regulation state changes, and can improve the efficiency while avoiding the output voltage drop phenomenon.

[0084] The above-mentioned embodiments do not constitute a limitation on the protection scope of the technical solutions. Any modification, equivalent replacement and improvement made within the spirit and principles of the above-mentioned embodiments shall be included in the protection scope of the technical solutions.

Claims

1. A dynamic voltage regulation phase control method for a multiphase switching power supply, wherein the multiphase switching power supply includes an N-phase power conversion circuit, where N is an integer greater than or equal to 2, the input terminal of the multiphase switching power supply receives an input voltage, and the output terminal is connected to an output capacitor to generate an output voltage, characterized in that... include: Determine whether the multiphase switching power supply is in the first dynamic voltage regulation state; When the multiphase switching power supply is in the first dynamic voltage regulation state, the number of operating phases changes relative to the state before the first dynamic voltage regulation state, based on a preset rate and multiple rate thresholds. The first dynamic voltage regulation state includes a dynamic adjustment of the output voltage increase state and / or a dynamic adjustment of the output voltage decrease state; when the multiphase switching power supply is in the first dynamic voltage regulation state, the output voltage is controlled to change according to the preset rate; the number of working phases is the number of phases of the power conversion circuit for power operation.

2. The dynamic voltage regulation phase number control method according to claim 1, characterized in that, When the first dynamic voltage regulation state includes a dynamic adjustment output voltage rise state, the preset rate includes a boost preset rate, and the multiple rate thresholds include multiple boost rate thresholds. When the multiphase switching power supply is in the dynamic adjustment output voltage rise state, the number of working phases is controlled to increase by the amount relative to the dynamic adjustment output voltage rise state before, according to the boost preset rate and the multiple boost rate thresholds. When the first dynamic voltage regulation state includes a dynamic adjustment output voltage reduction state, the preset rate includes a step-down preset rate, and the multiple rate thresholds include multiple step-down rate thresholds. When the multiphase switching power supply is in the dynamic adjustment output voltage reduction state, the number of working phases is reduced by the amount before the dynamic adjustment output voltage reduction state according to the step-down preset rate and the multiple step-down rate thresholds.

3. The dynamic voltage regulation phase number control method according to claim 1, characterized in that, The number of changes in the number of operating phases relative to the first dynamic voltage regulation state is obtained based on the preset rate and the plurality of rate thresholds; Based on the amount by which the number of working phases changes relative to the first dynamic voltage regulation state and the number of working phases before the first dynamic voltage regulation state, the amount by which the number of working phases changes relative to the first dynamic voltage regulation state is controlled.

4. The dynamic voltage regulation phase number control method according to claim 3, characterized in that, The number of working phases that need to be controlled to change relative to the first dynamic voltage regulation state is positively correlated with the preset rate.

5. The dynamic voltage regulation phase number control method according to claim 1, characterized in that, When the multiphase switching power supply is in the first dynamic voltage regulation state, the number of working phases is controlled to change by the amount of change relative to before the first dynamic voltage regulation state, based on the comparison result between the preset rate and the multiple rate thresholds.

6. The dynamic voltage regulation phase number control method according to claim 2, characterized in that, When the multiphase switching power supply is in the first dynamic voltage regulation state, the multiple rate thresholds are processed by the rate threshold bias to obtain multiple processed rate thresholds, and the number of working phases is controlled to change relative to the steady state before dynamic voltage regulation based on the comparison result between the preset rate and the multiple processed rate thresholds.

7. The dynamic voltage regulation phase number control method according to claim 6, characterized in that, The rate threshold bias is adjustable.

8. The dynamic voltage regulation phase number control method according to claim 6, characterized in that, When the first dynamic voltage regulation state includes a dynamic adjustment of the output voltage increase state, the rate threshold bias includes a first rate threshold bias. The first rate threshold bias is used to process the plurality of boost rate thresholds to obtain a plurality of processed boost rate thresholds. The plurality of processed boost rate thresholds are equal to the difference between the plurality of boost rate thresholds and the first rate threshold bias. Wherein, the first rate threshold bias is greater than or equal to zero.

9. The dynamic voltage regulation phase number control method according to claim 6, characterized in that, When the first dynamic voltage regulation state includes a dynamic adjustment of the output voltage reduction state, the rate threshold bias includes a second rate threshold bias. The second rate threshold bias is used to process the plurality of buck rate thresholds to obtain a plurality of processed buck rate thresholds. The plurality of processed buck rate thresholds are equal to the sum of the plurality of buck rate thresholds and the second rate threshold bias. Wherein, the second rate threshold bias is greater than or equal to zero.

10. The dynamic voltage regulation phase number control method according to claim 2, characterized in that, When the first dynamic voltage regulation state includes the dynamic adjustment of the output voltage increase state, and the number of controlled working phases increases by more than or equal to 1, at the moment when the multiphase switching power supply begins to enter the dynamic adjustment of the output voltage increase state, the corresponding number of power conversion circuits that have not been operating in power mode are simultaneously controlled to start operating in power mode.

11. The dynamic voltage regulation phase number control method according to claim 2, characterized in that, When the first dynamic voltage regulation state includes a dynamic adjustment output voltage reduction state, and the number of controlled working phases reduced by more than or equal to 2, the number of power conversion circuits performing power operation is gradually reduced when the multiphase switching power supply is in the dynamic adjustment output voltage reduction state.

12. The dynamic voltage regulation phase number control method according to claim 1, characterized in that, The plurality of rate thresholds are set according to the capacitance value of the output capacitor, and the plurality of rate thresholds are negatively correlated with the capacitance value of the output capacitor.

13. The dynamic voltage regulation phase number control method according to claim 12, characterized in that, The plurality of rate thresholds are obtained based on the optimal efficiency curve of the multiphase switching power supply and the capacitance value of the output capacitor.

14. The dynamic voltage regulation phase number control method according to claim 13, characterized in that, The optimal switching load current is obtained based on the optimal efficiency curve, and the plurality of rate thresholds are obtained based on the quotient of the difference between at least two optimal switching load currents and the capacitance of the output capacitor. Wherein, the optimal switching load current is the load current corresponding to the intersection point of the efficiency curves of adjacent operating phases of the optimal efficiency curve.

15. The dynamic voltage regulation phase number control method according to claim 12, characterized in that, When the multiphase switching power supply is in a steady state, the number of operating phases of the multiphase switching power supply is controlled according to the load current sampling signal and multiple current thresholds. The plurality of rate thresholds are obtained based on at least two of the plurality of current thresholds and the capacitance value of the output capacitor; The plurality of rate thresholds are obtained by dividing the difference between the current thresholds by the capacitance of the output capacitor.

16. The dynamic voltage regulation phase number control method according to any one of claims 12-14, characterized in that, The multiple rate thresholds are also set based on the number of working phases before the first dynamic voltage regulation state.

17. The dynamic voltage regulation phase number control method according to claim 1, characterized in that, The multiphase switching power supply receives a rate command and sets the preset rate according to the rate command.

18. A control circuit for a multiphase switching power supply, the multiphase switching power supply comprising an N-phase power conversion circuit, wherein N is an integer greater than or equal to 2, the input terminal of the multiphase switching power supply receiving an input voltage, and the output terminal connected to an output capacitor to generate an output voltage, characterized in that, The control circuit determines whether the multiphase switching power supply is in the first dynamic voltage regulation state. And when the multiphase switching power supply is in the first dynamic voltage regulation state, the number of working phases changes relative to the number before the first dynamic voltage regulation state according to a preset rate and multiple rate thresholds. The first dynamic voltage regulation state includes a dynamic adjustment of the output voltage increase state and / or a dynamic adjustment of the output voltage decrease state; when the multiphase switching power supply is in the first dynamic voltage regulation state, the control circuit controls the output voltage to change according to the preset rate; the number of working phases is the number of phases of the power conversion circuit for power operation.

19. The control circuit according to claim 17, characterized in that, The control circuit includes: The status judgment module detects the operating status of the multiphase switching power supply, determines whether the multiphase switching power supply is in the first dynamic voltage regulation state, and outputs a status judgment signal. The dynamic voltage regulation phase number control circuit receives the state characterization signal and outputs a dynamic voltage regulation phase number control signal according to the preset rate and the multiple rate thresholds when the state judgment signal indicates that the multi-phase switching power supply is in the first dynamic voltage regulation state. The control circuit controls the change in the number of operating phases relative to the first dynamic voltage regulation state based on the dynamic voltage regulation phase control signal.

20. A multiphase switching power supply, characterized in that, The control circuit as described in claim 18 or 19, or the number of changes in the number of working phases of the multiphase switching power supply using the dynamic voltage regulation phase control method as described in any one of claims 1-17.

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